D7100 'streaking'

First of all, I'm a very happy owner of a new D7100, it's a huge upgrade from a D90! I love how it forces me to become a better photographer (and perhaps buy more expensive glass :-)) since the resolution is unbelievable, exposing camera shake and my poor focusing skills.

Anyway, I had a feeling that exposure with D7100 was not quite what I was used to. So, today I shot some quick practice shots around the house to get a feeling of it. While there was no noticeable difference in exposure between my trusty D90 and the D7100, going into Adobe Lightroom 4.4 I noticed that one D7100 picture had minor streaking visible in the shadows. I pushed exposure by +2 and saw this:

D7100, blinds 'streaking' to the shadowed area

EDIT: Full size picture (above) not visible in the post, here's a smaller version:

I put the lens and the same settings to the D90 (1/200, f2.8, ISO200, White balance was Auto so the colors were off, lens used Nikkor 50mm 1.8G) and took another shot. After +2 exposure in Lightroom, this is what I got:

D90 - no 'streaking'

Actually, there probably is some streaking in the D90 shot as well, but it is almost impossible to see unless really looking for it. With the D7100, the streaks disappear when the right hand side gets more exposed (changing to ISO400 still slightly visible, at ISO800 not anymore).

Both images uploaded here were imported to Lightroom as DNG, WB set at 5500, exposure +2, and exported as full-size JPG at 85% quality. I can provide raw files if anyone needs those.

My questions regarding the streaking with D7100 are:

1) Is this normal/expected?

2) Is there something that can be done to this in post-processing, if (STRONG if) encountered in real photos?

3) If this is normal and can't be fixed in PP, in what situations I need to be careful with the shadow exposure? Please remember that the issue was visible even before pushing exposure.